This invention relates to improvements in the fabrication of multi-ply fibrous sheet structure, particularly of the soft absorbent type, such as, for example, paper towels.
In the fabrication of paper towels, efforts have been directed to improving the water holding capacity thereof involving, for example, such techniques as creping, puffing, peforating and the like to increase the surface area of the towel. Perforating has generally been effected using prior art embossing techniques in which pins are pushed through from one side of a web to leave outwardly extending projections of fibers on an exposed surface of the web.
The following U.S. Pat. Nos. are representative of the prior art, and are believed material to the Examination of this application:
2,281,945 discloses perforation of a multi-ply sheet A to form a plurality of small tufts or mounds B projecting away from surfaces of the sheet to enhance its cleansing action.
3,323,983 discloses apparatus for embossing superposed paper plies 14 between embossing rolls 10, 11 provided with mating pegs 12, 13.
3,546,056 discloses a sheet comprising plies of wadding 4, 5 on each side of an open mesh scrim 1. Pin embossments 25 project from one side of the sheet in provision of a roughened surface of improved cleansing action.
It is a general objective of the present invention to provide multi-ply sheet structure of improved absorbency and softness.
It is a further objective of the invention to provide apparatus for fabricating a multi-ply sheet structure of improved absorbency and softness.